usb/misc: usb4604: Use pm_ptr() macro

Use the newly introduced pm_ptr() macro, and mark the suspend/resume
functions __maybe_unused. These functions can then be moved outside the
CONFIG_PM_SUSPEND block, and the compiler can then process them and
detect build failures independently of the config. If unused, they will
simply be discarded by the compiler.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20200903112554.34263-9-paul@crapouillou.netSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/usb4604.c

@@ -112,8 +112,7 @@ static int usb4604_i2c_probe(struct i2c_client *i2c,
 	return usb4604_probe(hub);
 }
 
-#ifdef CONFIG_PM_SLEEP
-static int usb4604_i2c_suspend(struct device *dev)
+static int __maybe_unused usb4604_i2c_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct usb4604 *hub = i2c_get_clientdata(client);
@@ -123,7 +122,7 @@ static int usb4604_i2c_suspend(struct device *dev)
 	return 0;
 }
 
-static int usb4604_i2c_resume(struct device *dev)
+static int __maybe_unused usb4604_i2c_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct usb4604 *hub = i2c_get_clientdata(client);
@@ -132,7 +131,6 @@ static int usb4604_i2c_resume(struct device *dev)
 
 	return 0;
 }
-#endif
 
 static SIMPLE_DEV_PM_OPS(usb4604_i2c_pm_ops, usb4604_i2c_suspend,
 		usb4604_i2c_resume);
@@ -154,7 +152,7 @@ MODULE_DEVICE_TABLE(of, usb4604_of_match);
 static struct i2c_driver usb4604_i2c_driver = {
 	.driver = {
 		.name = "usb4604",
-		.pm = &usb4604_i2c_pm_ops,
+		.pm = pm_ptr(&usb4604_i2c_pm_ops),
 		.of_match_table = of_match_ptr(usb4604_of_match),
 	},
 	.probe		= usb4604_i2c_probe,